Problem 3. An efficiency study at a certain factory determines that the average worker who arrives on the job at 8 am will have assembled Q = -(2/3)+3 +2t2 + 18t transistor radios t hours later. (a) Find an expression for the efficiency E of the average worker t hours after arriving on the job at 8 am. (Hint: notice that the efficiency of the worker is the rate at which the worker assembles radios.) (b) How efficient is the average worker at 10 am? (c) At what times during the morning (8 am to 12 noon) is the average worker performing most and least efficiently? How efficient are they at those times